Dodge Challenger Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
486 Posts
Discussion Starter #1
Two Questions.

Is there a difference between TCS and BLD as described below in first two paragraphs?

When it says, under the Sport Mode description, that it disables the TCS isn't that the same as saying it disables the BLD? Yet the second paragraph says it remains active. ???


Traction Control System (TCS) This system monitors the amount of wheel spin of each
driven wheel. If wheel spin is detected, brake pressure is applied to the slipping wheel(s) and engine power is reduced to provide enhanced acceleration and stability.

A feature of the TCS system, Brake Limited Differential (BLD), controls the wheel spin across a driven axle. If one wheel on a driven axle is spinning faster than the other, the system will apply the brake of the spinning wheel. This will allow more engine torque to be applied to the wheel that is not spinning. This feature remains active even if TCS and ESC are in the “Partial Off” or “Full Off” modes. Refer to “Electronic Stability Control (ESC)” in this section for more information.

Track Mode
Track Mode is intended to be used when driving on a track. This raises the threshold for ESC activation further than Sport and also has track tuned TCS to improve vehicle performance while on a road course type track.

Sport Mode
Sport Mode is intended for times when a more spirited driving experience is desired. It also can be useful when wheel-slip may be desired such as driving out of deep snow, sand, or gravel. This mode disables the TCS portion of the ESC and raises the threshold for ESC activation, which allows for more wheel spin than what ESC normally allows.
 

·
Super Moderator
Joined
·
15,388 Posts
That's correct TCS utilizes the ABS system to achieve the BLD effect.

If the BLD is enough then it will also cut throttle and timing if excess wheelspin takes place.

ESP will use ABS, BLD and intervene the throttle / engine output to reign things in as well.

Different thresholds are in place.

I wonder if this is comparing to:

Leaving everything in Normal Mode, then:
>engaging partial ESP Off
>Full ESP Off

vs. using the Sport or Track modes

I can see for Track having some TCS operation to keep a wheel from excess spinning (even with Anti-Spin / Sure Grip diff) to achieve better track performance, whether in straight line or road course.

And with Sport mode to run disabled TCS altogether for those low-traction surfaces as described in the excerpt from the manual
 

·
Registered
Joined
·
486 Posts
Discussion Starter #3
That's correct TCS utilizes the ABS system to achieve the BLD effect.

If the BLD is enough then it will also cut throttle and timing if excess wheelspin takes place.

ESP will use ABS, BLD and intervene the throttle / engine output to reign things in as well.

Different thresholds are in place.

I wonder if this is comparing to:

Leaving everything in Normal Mode, then:
>engaging partial ESP Off
>Full ESP Off

vs. using the Sport or Track modes

I can see for Track having some TCS operation to keep a wheel from excess spinning (even with Anti-Spin / Sure Grip diff) to achieve better track performance, whether in straight line or road course.

And with Sport mode to run disabled TCS altogether for those low-traction surfaces as described in the excerpt from the manual
What I was asking is, aren't the descriptions of the TCS and BLD saying the same things? And then they go on to say "this feature(BLD) remains active, basically ALL the time. ???

So when you say, "Leaving everything in Normal Mode"... I guess that could be it but then we need a detail description of what if any effect the traction control button has in the selected drive modes. It's a bit confusing for my little brain.:surprise:
 

·
Super Moderator
Joined
·
15,388 Posts
What I was asking is, aren't the descriptions of the TCS and BLD saying the same things? And then they go on to say "this feature(BLD) remains active, basically ALL the time. ???

So when you say, "Leaving everything in Normal Mode"... I guess that could be it but then we need a detail description of what if any effect the traction control button has in the selected drive modes. It's a bit confusing for my little brain.:surprise:
It would probably help if someone had access to a WiTech system to see what settings take place with ESP and TCS in the different modes Normal, Sport, Track to see what levels it sets the parameters for.

The systems are factoring in steering angle sensor, yaw sensor, throttle %, rpm, and what VSS vs. the tone ring readouts from each wheel to do all their work.

I remember when trying to dyno my '01 Benz for baselines prior to cam swap and tuning that additional steps had to be taken to disable these systems. Even with the "ESP off" button, the TCS would intervene on the dyno.

We had to track down the two fuses for the ESP / TCS system and pull them to get around having it intervene and interfere with running on the dyno.
 

·
Registered
Joined
·
486 Posts
Discussion Starter #5
It would probably help if someone had access to a WiTech system to see what settings take place with ESP and TCS in the different modes Normal, Sport, Track to see what levels it sets the parameters for.

The systems are factoring in steering angle sensor, yaw sensor, throttle %, rpm, and what VSS vs. the tone ring readouts from each wheel to do all their work.

I remember when trying to dyno my '01 Benz for baselines prior to cam swap and tuning that additional steps had to be taken to disable these systems. Even with the "ESP off" button, the TCS would intervene on the dyno.

We had to track down the two fuses for the ESP / TCS system and pull them to get around having it intervene and interfere with running on the dyno.
Don't know what a WiTech system is, but it sounds like that's exactly whats needed.
 

·
Super Moderator
Joined
·
15,388 Posts
The WiTech system is what the dealers use - it can delve deep into all the systems to see what's taking place.

I've seen what the Star system (Mercedes) has and it reads the various modules and the peripherals and systems attached to it.

One example, is the PCMs can be set to operate for the various systems NAFTA, Euro, etc standards for the market the vehicle is exported to.

It would be educational to see what the various modes do with all the Sport / Track settings, since this affects engine / trans (A8) / ESP / TCS and shocks (SRT) to understand it further.
 

·
Super Moderator
2016 SXT Plus Blacktop
Joined
·
16,976 Posts
From my reading, the TCS uses all resources, wheel braking and engine power reduction

The BLD only does the wheel braking on the spinning wheel. Full engine power remains, and more torque of that full power is applied to the other wheel.

Since BLD is a subset of TCS, it only does a partial mitigation. What happens if the now additional torque wheel starts to spin too? Braking on both? Hmmm

A Guy
 

·
Registered
Joined
·
178 Posts
BLD works great in the Jeep JK’s, but it only works in 4wd, didn’t know you can have BLD with a 2wd application.
 

·
Super Moderator
Joined
·
15,388 Posts
BLD works great in the Jeep JK’s, but it only works in 4wd, didn’t know you can have BLD with a 2wd application.
Daimler has been using BLD for years - they rarely had limited slip differentials and instead used BLD
 

·
Registered
Joined
·
486 Posts
Discussion Starter #10
Daimler has been using BLD for years - they rarely had limited slip differentials and instead used BLD
Yes, I remember when Traction Control was first introduced and that it was just as they describe what BLD does.
 

·
Registered
Joined
·
178 Posts
Daimler has been using BLD for years - they rarely had limited slip differentials and instead used BLD
And it works great, i've had Toyota/Nissan vehicles equipped with similar technologies, Jeep does beat them hand down, and without having to press any buttons.
You can fast forward here to 1:42min, that's me and my Jeep without lockers or any other traction device, you can see basically one wheel in in the air front, and another one rear, and BLD in full action when that happens. later on i added a locker in the back, and went with a detroit Truetrac in the front, for extra traction.


 
1 - 11 of 11 Posts
Top